Abstracts (first author)
Population structure of microparasites infecting Daphnia: spatio-temporal dynamics
Surprisingly, in many field studies of natural host-parasite systems genetic changes have been investigated for one player only – the host. This is astonishing as coevolution requires changes in the frequencies of both players. The previous restrictions were mainly caused by limited access to molecular markers for unculturable microparasites. Recently, we have established a NGS protocol to shed light on the genetic changes within populations of Caullerya mesnili (Ichthyosporea), the parasite of the waterflea Daphnia. This parasite is one of the most common pathogens of European Daphnia species that inhabit large, permanent lakes. We show that the genetic structure of parasite populations varies both over space and, most interestingly, over time. Given its high virulence (up to 95% fecundity reduction), strong genetic specificity for infection, large prevalence in natural populations (up to 40%), and currently established molecular tools - Caullerya is a strong candidate to become a model parasite for future coevolutionary studies of natural host-parasite systems. Our preliminary studies show that the genetic structure of parasite populations varies both over space and, most interestingly, over time. In the near future, the new molecular and bioinformatical techniques will allow to track changes in genetic population structure on a large scale for the often unstudied member of a coevolutionary pair – the parasite.